1. Field of the Invention
This invention relates to an integrated self-cleaning air filter assembly for a vehicle air intake system having active noise control.
2. Related Art
Internal combustion engines include air induction systems for conducting air to the engine. Engine noise is propagated through the air induction systems, which is undesirable. Noise attenuation mechanisms have been installed within the air induction systems to reduce these noises. Typically these noise attenuation mechanisms include a speaker, a sound detector, a signal generator, and various other components that are used to reduce noise generated within the air induction system. These components are mounted inside an air duct housing.
The air that is drawn into the air induction system includes dust, dirt, and other particulate contaminants. These contaminants can clog the engine resulting in poor performance. An air filter is typically installed within the air induction system to remove these contaminants from the airflow prior to the air being drawn into the engine. When operating under heavy dust conditions, the air filter can quickly become clogged, requiring replacement. This results in poor engine performance and significant vehicle downtime to replace the filters, which is undesirable. Additionally, each replacement filter has poor initial filter efficiency because the holes in the new filter must be partially plugged with a first dust exposure to achieve the optimal filter efficiency.
It is the object of the present invention to provide a simple and effective apparatus and method for cleaning the air filter to overcome the deficiencies outlined above.
An air induction system with active noise control draws in air to operate a vehicle""s internal combustion engine. The air that is drawn into the system includes contaminants such as dust and dirt particulates that can clog the engine. The subject air induction system includes a self-cleaning air filter that is integrated within an air intake housing. The self-cleaning filter is preferably powered and controlled by the same electronic unit that is used to power the active noise control system.
In a preferred embodiment, the system includes an air intake housing having an inlet and an outlet and defining an airflow passageway between the inlet and the outlet. An active noise control assembly for reducing noise levels and the air filter are mounted within the housing. The filter includes a self-cleaning mechanism selectively actuated to remove particulates trapped within the filter under predetermined conditions. The system also includes a dust-dumping valve that is mounted underneath the filter to remove particulates from the air intake housing upon activation of the self-cleaning mechanism.
In one embodiment, the self-cleaning mechanism includes piezo-electric material that is in direct contact with the filter. The piezo-electric material provides a vibrational input force to the filter upon receipt of an electronic control signal to break free particulates from the filter.
In another embodiment, the self-cleaning mechanism includes a pressure pulse device to provide intermittent pressure pulses to remove particulates from the filter. The pressure pulse device includes an air compressor, a plurality of venturi air pulse directors spaced about the air filter, and a plurality of solenoids for providing pulsing input forces for air flowing through the venturi air pulse directors to blow the particulates free from the filter.
Preferably, the self-cleaning mechanism is comprised of both a vibration and pressure pulse device. The air filter is simultaneously vibrated and subjected to air pressure pulses to loosen and remove particulates from the filter.
The method of cleaning the air filter in an air induction housing with an active noise control system includes the following steps. A filter check diagnostic cycle is initiated to determine a filter dirt level, the filter dirt level is compared to a predetermined limit, and a self-cleaning mechanism is automatically actuated when the filter dirt level exceeds the predetermined limit to remove particulates from the filter. Additional steps include vibrating the air filter and/or directing air pulses at the air filter to remove particulates, and removing the particulates from the air intake housing.
The subject apparatus provides a simple method for automatically cleaning the air filter in an air induction system with active noise control. This results in reduced engine wear and can significantly extend filter life and possibly even eliminate the need for replacement filters.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.